Process for preparing polymeric, ionic imidazolium compounds

Abstract

A process for preparing polymeric, ionic compounds comprising imidazolium groups (polymeric, ionic imidazolium compounds for short) comprising reacting an a-dicarbonyl compound, an aldehyde, —at least one amino compound having at least two primary amino groups (referred to as oligoamine), if appropriate an amino compound having only one primary amino group (referred to as monoamine) and a protic acid, wherein the protic acid is placed in the reactor and the oligoamine or the aldehyde and o dicarbonyl compound or the oligoamine, the aldehyde and α-dicarbonyl compound are fed to the protic acid.

The invention claimed is: 
     
       1. A process for preparing polymeric, ionic compounds comprising imidazolium groups, the process comprising reacting:
 an α-dicarbonyl compound, 
 an aldehyde, 
 at least one oligoamine, which is an amino compound having at least two primary amino groups, 
 optionally a monoamine, which is an amino compound having only one primary amino group; and a 
 protic acid, 
 at a pressure of from 0.1 to 10 bar and at a temperature of less than 100° C., 
 wherein the protic acid is first placed in the reactor only and then the oligoamine, the aldehyde and α-dicarbonyl compound are fed to the protic acid in the reactor, 
 wherein the protic acid and the oligoamine are in a molar ratio of from 1.05:1 to 10:1. 
 
     
     
       2. The process according to  claim 1 , wherein a pH value of the reaction solution is from 1 to 6. 
     
     
       3. The process according to  claim 1  wherein a molar ratio of the α-dicarbonyl compound to the oligoamine is greater than 1. 
     
     
       4. The process according to  claim 1 , wherein a molar ratio of the aldehyde to the oligoamine is greater than 1. 
     
     
       5. The process according to  claim 1 , wherein the α-dicarbonyl compound is a compound of formula I:
   R1-CO—CO—R2
 
 wherein R1 and R2 are each, independently of one another, an H atom or an organic radical having from 1 to 20 carbon atoms. 
 
     
     
       6. The process according to  claim 1 , wherein the aldehyde is an aldehyde of formula II:
   R3-CHO 
 wherein R3 is an H atom or an organic radical having from 1 to 20 carbon atoms. 
 
     
     
       7. The process according to  claim 1 , wherein the aldehyde is formaldehyde. 
     
     
       8. The process according to  claim 1 , wherein the oligoamine is a compound of formula III:
   (NH2 —) n R4
 
 wherein n is an integer greater than or equal to 2 and R4 is any n-valent organic radical. 
 
     
     
       9. The process according to  claim 1 , wherein the oligoamine is an aliphatic or aromatic diamine or triamine. 
     
     
       10. The process according to  claim 1 , wherein the oligoamine is a C2-C20-alkylenediamine. 
     
     
       11. The process according to  claim 1 , wherein the protic acid is an acid with a pK a  greater than 1. 
     
     
       12. The process according to  claim 1 , wherein the protic acid is acetic acid. 
     
     
       13. The process according to  claim 1 , wherein the process is carried out in water, in a water-miscible solvent or a mixture thereof. 
     
     
       14. The process according to  claim 1 , wherein the carbonyl groups of the α-dicarbonyl compound and the aldehyde are in the form of a hemiacetal, an acetal, a hemiketal, or a ketal group. 
     
     
       15. The process according to  claim 1 , wherein the aldehyde is formaldehyde and the formaldehyde forms compounds that liberate formaldehyde.